Thumb lock



May 29, 1923.

A. GAMWELL THUMB LOCK Filed May 2. 1922 LVI/E N TOR.

' A TTORNEY.

Patented May 29, 1923. l

- uis sii-Mrs 'pqT E NT: orrice.

` ARTHUR GAMWfELL, or LosxANGELEs; cALIroRNIA'.

struct third; to" provide a combination look that has key cntrolledlatch levers with-a safetydogtherebetween; i v v- A further.object-:ofmy vinvention. is to provide an apparatus' that is too small'` andlightl for use by -prisoners as a weapon- Referring: to thedra-wingFigure 1 rep'- i'esents a top viewof my thumb lock in its actual size.-i l Figure represents '-aj side view of` F igure :1. fri 'i v Figure 3represents a fragmentary top viewz ofl my;v thumb lock.' in .enlargedproportions.

Figure 4' represents sectional view on line 4-4 of Figure 3.

Figure 5 represents a partsectional view on line 5-5 of Figure 4, withparts removed.

Referring to the drawing in which like characters yof referencedesignate similar parts, the top and bottom plates 1 and lL respectivelyare secured together, with the spacers 2 and 3 in the 'outer centralportions thereof, the arms 4 are integral with the said plates 1 andPand reach semicircularly from the two end portions thereof to thejoints 24, the said joints 24 are positioned in the outer end portionsof the arms 4 and the fingers 5, the said fingers 5 are operativelypositioned between the arms 4 and the plates 1 and 1athe said lingers 5reach semicircularly from the joints 24 to the free inner ends thereof,the teeth 12a are formed in the outer circular faces of the fingers 5,and extendk back therefrom a distance with the oints 24 as the axisthereof, the latches 6 are operatively positioned on the pins 21, andthe pins 21 are-,in turn secured in the plates 1 and l, the teeth 12 areformed in the upper-outer end portions vflanges 14 and 1922. `Seria1 No.557,990.

l of; the latches '6 and meshl with the teeth 12a when pressedtogether,the shoulders 18 are formed inthe upper-inner end `*portions of thelatches 6, and the flanges 14k are integral with the latches6andextendtherefro1n von the innerlower portions to the cams 1,5', thecams 15 vare integral with the said flanges 14 and are formed to suit avkey positioned thru the holes 11,l the; said holes 11 pass thru thesaidtop and bottom platesvl and 1a respectively, the springs 9` arepositioned between fthe outer-lower portion of the the -inner portion'`of the flanges 13, thefianges 13 are integral with thel said-spacer 3`and .extend upwardly a ldistance adjacent to thek teeth 12a onl thefingers ``The dog 7-v is operatively .positionedfon the pins 2.0 vandf8, thruv the slot :19 and the spacer 2respectively, the slot 19; passesthru the dog. 7 with the llonger diameter thereof lying on thevcenterline of the-dog 7, andthe pin 8 is in turn securedy to.theupper-central portion of the dog 7 andentends` upwardlytherefrom onthe said center,y line .thereon the. arms 1-7 are integral with the twosides of the dog 7` and extend therefrom a distance over the said.latches 6, theshoulderslkl areformed inthe .two sides. of thedog 7atfpoint's below` .thearms 1-7 `to fitj in the vcorrespond,- ingshoulders 18 in the ysaid llatches 6, the cam 16 is integral with thelowerrnost-cen- 'tral portionxof the 'dog 7, and is formed to suit thekey positioned thru the said holes 11.-

The slot 26 is formed in the upper-side face of the dog 7, adjacent tothe plate 1a, and extends from one side thereof tok the other, thespring 10 is preferably elliptic in form and is positioned in the slot26, and bears slidably against the said plate 1a.

The slide 22 is operatively secured' on the outer surface of the spacer2 by the pin 23 and over the sai-dpin 8, the bevel face 25 is positionedadjacent to the said pin 8, and

bears slidably thereover, the said pin 23l passes operatively thru theslot 27 and is inl turn secured to vthe spacer 2, and the slot 27 passesthru the said slide 22 with the larger diameter thereof in line with thetravel thereof. 1 'n l To fasten my lock on ya prisoners thumbs,

ioo

the teeth 1 2 in the latches Gare first released i from the teeth 12a inthe fingers 5, by inserting a suitable key thru the holes 11 in theplates 1 and 1a, the said key is then turned to lift the cam 16, againstthe sliding resistance of the spring 10, to release the shoulders 18 inthe dog 7 from the shoulders 18 in the latches 6, and when the saidshoulders 18 are released from one another, the cam 15 is in turn moveddownwardly against the tension of the spring 9, to swing the latch 6 onthe pins 21 to release the said teeth 12 from the teeth 12a.

The dog 7 slides up on the pins 2O and 8, in the slot 19 and spacer 2respectively, when the cam 16 islifted to release the said shoulders 18from one another, and the arms 17 limit the downward movement of thesaid dog 7, by striking on the top faces of the latches 6 When the dog 7is in its raised position free from the latches 6, the prisoners thumbsare placed between the arms 4 and the lingers 5, the said lingers 5 arethen closed by swinging on the joints 24 between the plates 1 and l, andthe arms 4. to mesh the teeth 12a in the sa'id lingers 5, into the teeth12 in the said latches 6, to slidably pass over one another to grip thethumbs. lt will seen that when the teeth 12a slide over the teeth 12,.when gripping the thumbs, the latches 6 will swing on the pins 21, whenthe bevel laces between the said teeth 12 and 12 slide over one another,to give the desired grip around the thumbs as hereinbefore described,and the lingers 5 are then held in place by backing the projecting facestogether which are positioned between the said bevel Jfaces in the teeth12a and 12 respectively.

After the thumbs arelocked in place 'as hereinbetore described, thelatches 'are prevented troin backing away from the lingers when meshingthe shoulders 18 together by lowering the dog 7 on the pins 19 and 8.The dog 7 is lowered by moving the bevel faces 25, in the slide 22sidewavs. nvmthe outer end' portion of the said pin 8. y

The slide 22 preventsthe prisoner from raising the pin 8 to release thedog 7 from the shoulders 18, and the flanges 13 also pre vent probinginto the'inner working parts of the said lock.

Having thus described my invention, I claim:

1. A thumb lock of the class described, comprising a body portion incombination with a set of extended arms positioned on each end thereof,a pair vof swinging lingers adapted to he positioned between the saidextended arms, toothed latches adapted to enwth the said swinginglingers, a dog adapted to hold the said latches in a locked position. areleasing means adapted toV disengage the said dog from the toothedlatches and the said toothed latches lfrom the swinging lingers, as setforth.

2. A. thumb lock of the class described, comprising a central enclosedhousing. arms extending from two sides of the said housing, lingersoperatively positioned in the lend portions of the said arms, latchesadapted to slidably engage with the said fingers, a dog adapted te holdthe said latches locked with the said lingers, a releasing means adaptedto disengag'e the said dog `from the said latches, a key adapted torelease the said latches from the said fingers, a guard means adapted toprevent picking the said lock, as set forth.

In testimony whero I aiiix my signature.

ARTHUR GAMWELL.

